The present invention relates to machine tools, and more particularly, to a cutting tool that includes a cutter body along with a locking screw and an adapter. More specifically, the invention relates to the locking screw alone, as well as the combination of the locking screw with other components(s), that provide improved coolant delivery to the cutter body. Further, the invention relates to an improved locking screw, as well as the combination of the locking screw with other components(s), that provide an improvement to the design flexibility of the cutter body.
In a conventional cutting arrangement, a cutter body retains or holds one or more cutting inserts. The cutter body operatively attaches to a machine such as, for example, a milling machine. An adapter is useful for the attachment of the cutter body to the milling machine wherein the locking screw secures the cutter body to the adapter. Typically, the milling machine drives the cutter body so as to rotate the cutter body. Upon rotation, the cutting inserts engage the workpiece material thereby removing material from the workpiece. It is typical that heat is generated at the interface between the cutting insert and the workpiece material.
Heat generated due to the material removal process can be detrimental to the integrity of the cutting insert. For example, a cutting insert made from cemented tungsten carbide maintains its integrity up to a certain temperature. If the heat generated and passed along to the cutting insert causes the temperature to rise above a certain limit, the cutting insert can be susceptible to plastic deformation. Plastic deformation is detrimental to the cutting insert in that it can result in the failure of the cutting insert. Heretofore, one way to help alleviate heat-related cutting insert failure has been to supply coolant to the cutting insert or to the vicinity of the cutting insert-workpiece interface.
The following patent documents are exemplary of ways to supply coolant to the cutting insert or to the vicinity of the cutting insert-workpiece interface: U.S. Pat. No. 5,237,894 to Lindeke; U.S. Pat. No. 5,275,633 to Johansson et al.; U.S. Pat. No. 5,439,327 to Wertheim; U.S. Pat. No. 6,045,300 to Antoun; U.S. Pat. No. 6,299,388 to Slabe; U.S. Pat. No. 6,652,200 to Kramer; U.S. Pat. No. 7,125,207 to Craig et al.; German Patent 30 04 166 to Sandvik A B; and French Patent 2 244 590 to Georges.
Even though arrangements exist that provide delivery of coolant, there remains a need to improve the way the assembly supplies coolant to the cutting insert and/or to the vicinity of the cutting insert-workpiece interface. This is the case when it comes to the volume (or size) of the supply of coolant available for delivery to the cutting insert and/or to the vicinity of the cutting insert-workpiece interface. There would be a benefit to provide an assembly through which there is an increase in the supply of coolant for delivery to the cutting insert and/or to the vicinity of the cutting insert-workpiece interface. This benefit would comprise either supplying a greater volume of coolant to the cutting insert and/or to the vicinity of the cutting insert-workpiece interface or increasing the number of cutting insert seats and cutting inserts on the assembly.
It would therefore be highly desirable to provide a locking screw, which is a component of the entire assembly, to facilitate an increase in the volume of coolant available for delivery to the cutting insert and/or the vicinity of the cutting insert-workpiece interface over what has been available heretofore. It would also be highly desirable to provide a locking screw in combination with other components(s) to facilitate an increase in the volume of coolant available for delivery to the cutting insert and/or the vicinity of the cutting insert-workpiece interface over what has been available heretofore.
In some typical cutting tools, the basic components comprise a cutter body (which carries the cutting inserts), an adapter and a locking screw. The cutter body contains a pilot hole which receives a pilot projecting from the adapter. The locking screw secures the cutter body to the adapter. Coolant travels from the coolant source into the adapter and then into and through the locking screw. Coolant exits the locking screw through the outlet of a transverse bore into a coolant passage in the cutter body and discharges toward the cutting insert. Heretofore, the coolant passage in the cutter body had to be in fluid communication with the outlet of the transverse bore of the locking screw. Thus, the entrance to the coolant passage has been restricted to a location above (axially forward) the location where the locking screw seats on the cutter body. Such a design restriction has limited the design of the cutter body. It would be highly desirable to provide a locking screw, as well as a combination of the locking screw with other component(s), that expands the locations for the entrance to the coolant passage in the cutter body.
One such location for the entrance to the coolant passage would be below (axially rearward) the location where the locking screw seats on the cutter body. Thus, it would be highly desirable to provide a locking screw, as well as a combination of the locking screw with other component(s), that expands the location for the entrance to the coolant passage in the cutter body to be below (axially rearward) of the location where the locking screw seats on the cutter body.